In a conventional ultrasonic motor, a high-frequency voltage is applied to a piezoelectric element to ultrasonically vibrate a vibrator fixed to the piezoelectric element. The ultrasonic vibration of the vibrator generates a driving force between a friction member and the vibrator pressed against the friction member. This motor can maintain high output even in a compact size. For example, PTL 1 discloses an ultrasonic motor using a compact vibrator. In addition, various contrivances for the efficient transmission of a driving force to a driving target body have been introduced into the ultrasonic motor. For example, in the ultrasonic motor disclosed in PTL 2, a rolling member is clamped by the resultant force of a pressing force given to the vibrator or its reactive force and the biasing force of a transmission member supported by a driving target body.